The present invention relates to a thermoplastic resin composition which is excellent in a mechanical strength a moisture resistance and a fluidity and a molded article. More specifically, the present invention relates to a resin composition comprising a polycarbonate resin and a lactic acid based resin which is improved in a hydrolysis resistance to a large extent and excellent in a mechanical strength such as a thin-walled falling weight impact strength and an Izod impact strength and a molded article comprising the above resin composition. The thermoplastic resin composition of the present invention can be used in the electric and electronic field such as office automation equipments, information and communication equipments home electric appliances and the like, the automobile field, the construction field and the like.